Safety early warning system of subway tunnel

The invention relates to a safety early warning system of a subway tunnel. The safety early warning system comprises fire monitoring devices, automatic fire alarm devices, control centers arranged at stations of a subway tunnel, and stress monitoring devices and subway deformation monitoring and alarming devices; the fire monitoring devices and the automatic fire alarm devices are arranged along a subway tunnel; and the stress monitoring devices and subway deformation monitoring and alarming devices are arranged along the subway tunnel. The fire monitoring devices include temperature-sensing cables laid inside the subway tunnel; temperature detectors are arranged at the temperature-sensing cables at an interval of 80 centimeters; and the automatic fire alarm devices are arranged next to the temperature detectors. The stress monitoring devices and the subway deformation monitoring and alarming devices that are arranged in an integrated mode are fixed at the wall of the subway tunnel along the length direction of the subway tunnel. Therefore, security of cables of the subway tunnel can be guaranteed. The system plays a role in early warning of security of the subway tunnel and has advantages of high reliability, simple wiring, and low maintenance cost.